Process and apparatus for producing yarn

ABSTRACT

Process and apparatus for converting a tow composed of a multiplicity of substantially continuous synthetic textile filaments into a sliver or strands of staple length textile fibers by stretch breaking the tow. The tow is evened and portions of the filaments are differentially laterally deflected. The apparatus includes movable deflecting blades in rotating blade holders, said blades having a contour to provide peaks and valleys and a second set of movable blades in rotating blade holders, said blades having straight edges. The blade holders rotate so that the blades of each alternate in engagement with the tow.

United States Patent Lohrke, Jr.

[ 51 Oct. 10,1972

[54] PROCESS AND APPARATUS FOR PRODUCING YARN [72] Inventor: James L.Lohrke, Jr., Birmingham Township, Chester City, Pa.

[73] Assignee: Turbo Machine Company [22] Filed: Dec. 14, 1970 [21]Appl. No.: 98,209

Related US. Application Data [63] Continuation-impart of Ser. No.794,238, Jan.

27, 1969, abandoned.

52 us. Cl ..19/.37 51 Int Cl. ..D01g 1/00 [58] Field of Search ..19/.3,.64, 65 T, 66 T [56] References Cited UNITED STATES PATENTS 3,500,5043/1970 Oguchi et a1. l9/.37

Primary Examiner-Dorsey Newton Att0rneyPaul & Paul [57] ABSTRACT Processand apparatus for converting a tow composed of a multiplicity ofsubstantially continuous synthetic textile filaments into a sliver orstrands of staple length textile fibers by stretch breaking the tow. Thetow is evened and portions of the filaments are differentially laterallydeflected. The apparatus includes movable deflecting blades in rotatingblade holders, said blades having a contour to provide peaks and valleysand a second set of movable blades in rotating blade holders, saidblades having straight edges. The blade hol ders rotate so that theblades of each alternate in en gagement with the tow.

5 Claims, 5 Drawing figures PROCESS AND APPARATUS FOR PRODUCING YARNCROSS-REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of my prior copending application Ser. No. 794,238,filed Jan. 24, 1969, now abandoned, for Process and Apparatus forProducing Yarn, and discloses and claims in part the subject matterdisclosed and claimed in that application.

BACKGROUND OF THE INVENTION This invention relates to a process andapparatus for converting a tow composed of a multiplicity ofsubstantially continuous synthetic textile filaments into a sliver orstrands of staple length textile fibers.

In US. Pat. No. 1,883,384, granted to James Louis Lohrke (Sr.) and HenryH. Perry on Oct. 18, 1932, there is disclosed a process for thecontinuous conversion of tow of continuous textile filaments into sliverand/or yarn, by subjecting the-filaments to a tensioning action ordrafting, thereby breaking the individual filaments into staple lengthfibers, but, at the same time, preserving their relative parallelism.

U.S. Pat. No. 2,419,320, granted to James Louis Lohrke (Sr.) on April22, 1947, disclosed an improvement in the continuous conversion of towinto staple length sliver by drafting and subjecting the tow to anintermittent transverse deflection action out of its normal path. Suchaction of deflecting the tow out of its normal path intermittently,resulted in improved control over fiber length in comparison to the purestretch breaking earlier disclosed in US. Pat. No. 1,883,384 where nodeflection device was used.

The process of US. Pat. No. 2,419,320 has become commercially acceptedand is one of the major means of converting synthetic fiber tows intoslivers for spinning into yarns. One textile machine using thisprinciple is the Turbo Stapler, manufactured by the Turbo MachineCompany of Lansdale, Pa. Textile mills throughout the world havepurchased the Turbo Stapler primarily for the continuous conversion ofacrylic tows into sliver by stretch breaking for spinning into yarns forthe knitting trades.

Practical textile mill experience has shown that the process asdescribed in US. Patent No. 2,419,320 and utilized by the Turbo Stapleris highly critical in respect to the levelness of the tow entering thestapler. Generally, it is ideal to have the tow sheet of a uniformthickness of 15 fibers in height. However, it has so far not beenpossible for the synthetic fiber producers to manufacture commercially atow of uniform thickness. Commercially manufactured tow will normallyhave sections with as few as fibers in height, or less, and othersections with as many as 30 fibers or more. This large variation in thenumber of fibers in height in the tow sheet results in a variation inthe effect from the deflecting devices and this, in turn, results in aloss of variation of the effect of the deflection devices between thethin sections where the deflecting devices act more or less directly onindividual fibers, and .the thick sections, where the deflecting devicescanact only'on the fibers near the top of or near the bottom of the towsheet. Those fibers within the center of the tow sheet are more or lessshielded from the deflection action by the outer fibers. There is nosubstantial realignment of the distribution of the longitudinallyextending fibers-across the width of the two band.

In US Pat. No. 3,500,504 a further method of producing sliver directlyfrom tow is disclosed. The

sliverproduced by this method includes a large portion of cut fibers.The patentee sets forth what he considers to be hisimprovement over thestandard Turbo stretch breaker and the well known deflecting stretchbreaker, emphasizing the fact that his improvement consists of cuttingthe fibers and that the larger the amount of cut fibers in the tow as itpasses through the breaking zone, the smaller is the breaking forcerequired in the system.

In actual practice, the device in accordance with this SUMMARY OF THEINVENTION The present invention is an improvement both in process andapparatus over the deflecting devices earlier shown and embodies thefeature that all fibers can be subjected to direct deflection, eventhough they be within a fairly thick section of the tow sheet.Therefore, thick sections of the tow sheet are acted upon more or lessin the same manner as thin sections. Further, it is possible to processtow sheets with a thickness greatly in excess of 15 fibers in height,while at the same time preserving control of the length of the fibersproduced.

The present invention is directed specifically to an improved process ofand apparatus for stretch breaking tow. The fibers of the tow sheet aresubjected not only to transverse deflection, but also to lateraldeflection. The distribution of filaments in the tow sheet is evened bya process in which the filaments are separated into bundles andalternately returned to a more homogeneous mass prior to reseparation.The evening process and lateral deflection process take place across asubstantially flat bar which coacts with the tow band to flatten andspread the bundles and differentially deflect them laterally therebyimpressing stresses at different points within the bundles as they arepresented in the device for stretch breaking.

The primary object of the present invention is to improve the knownmethods of stretch breaking tow.

Another object is to provide an improved tow deflecting device in astretch breaking apparatus for processing the currently available,substantially nonuniform tow.

A further object of the present invention is the improvement in controlover staple fiber length over present tow deflecting devices with anygiven quality of tow sheet levelness.

Other objects and advantageous features of the invention will beapparent from the following description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The nature and characteristic featuresof the invention will be more readily understood from the followingdescription taken in connection with the accompanying drawings formingpart thereof in which:

FIG. 1 is a schematic elevation of apparatus tostretch break tow intostaple length sliver utilizing the present invention;

FIG. 2 is an enlarged transverse sectional view, taken approximately onthe line 22 of FIG. 1;

FIG. 3 is a sectional view, taken approximately on the line 3-3 of FIG.2;

FIG. 4 is a fragmentary view of a portion of a modified form ofdeflecting blade; and

FIG. 5 is a diagrammatic view showing a modified form employing adifferent number of blades in the blade holder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularlyto FIG. 1, there is shown an apparatus for stretch breaking tow ofcontinuous filaments of synthetic fibers into staple length fibers insliver form.

Driven rollers and 11 are provided to draw the tow 12 into the machine.The tow 12 then passes to and between driven rollers 14 and 15 whichtension the tow 12, or when required stretch the tow 12, in the presenceof heat if desired, to reduce the diameter of the filaments. The tow 12then passes to and between driven rollers 16 and 17, which have a highersurface speed than the roller pair 14, 15 causing a further tension tobe applied to the fibers.

lnterposed between the roller pair 14, 15 and the roller pair 16, 17,the deflecting device 20 to accomplish the desired deflection isprovided.

The deflecting device 20 preferably includes a pair of blade holders 21and 22, shown in more detail in FIGS. 2 and 3, secured to drive shafts23 and 24; gears 25 and 26 being provided for rotating the shafts 23 and24 and the blade holders 21 and 22 in unison.

One of the blade holders, such as the blade holder 21, is provided witha plurality of blades 30 having along their exposed edges aconfiguration to provide spaced peaks 31 and valleys 32. One preferrededge profile for this purpose is composed of straight meeting edges 33and 34 with apexes at the peaks 31 providing a saw tooth.

Other blade profiles could be employed such as that shown in FIG. 4 inwhich a blade 36 is illustrated having a sinuous profile with peaks at37 and valleys at 38.

The blades 30, as shown in FIG. 2, are mounted in the blade holder 21 sothat the respective peaks 31 and valleys 32 are offset or staggered. Asillustrated, the peaks 31 on successive blades are each advancedlaterally one quarter of or distance between the peaks 31. Between theblades 30 on the blade holder 21 there are clearance grooves 39 with adepth about two thirds the depth of the blades 30.

The other blade holder 22 has a plurality of blades 40 with straightedges 41. The blade holder 22 has clearance grooves 39 between theblades 40 like those of the blade holder 21. The blades 40, just as theblades 30, are designed to extend across the full width of the tow bandand beyond both edges thereof.

As the tow sheet 12 is advanced first by the rollers 10, 11 then by therollers 14, 15 with tensioning, and further advanced with furthertensioning by the rollers 16 and 17, the fibers are subjected to theaction of the deflecting device which is arranged as clearly illustratedin FIG. 1 in a similar fashion to the Lohrke US. Pat. No. 2,419,320, sothat the blades on the rotating blade holders deflect the towvertically, that is, transversely from its normal path of travel. Inaddition, because of the particular blade configuration and arrangementof blades in accordance with this invention the tow is evened anddifferentially deflected laterally, that is, across the width of theband.

As each blade 30 advances to the tow sheet 12, the peaks 31 penetratethe sheet and the edges of the teeth deflect the filaments laterallyfrom their normal path and also separate them into bundles or groups offilaments. As the next blade 30 advances its peaks 31 penetrate the towsheet 12, but at different locations offset from the previous areas ofpenetration. Since the blades and blade holders are arranged so that theblades 30 alternate with the blades 40 in engaging the tow, the nextblade to engage the tow will be a straight edged blade 40. This willengage the tow from the opposite surface. This blade not onlytransversely, that is, vertically, deflects the tow sheet, but also, incoaction with the tow sheet itself, the individual filament bundles, andthe blade 30, deflects the filaments laterally so that the filaments aredrawn across the flat edge of the blade 40. The straight edges 41 of theblades 40 bring the tow sheet back to a relatively flat configuration inthat they tend to flatten the bundles and spread them out so that theytend to come together once again in a more homogeneous mass. At the sametime since the bundles comprise a plurality of filaments and since thefilaments are spaced at various levels along the sloping surfaces of theteeth, these filaments are differentially subject to lateral drawingacross the straight surface of the blade 40.

As the next blade 30 advances its peaks 31 penetrate the tow sheet 12,but at different locations offset from the previous areas ofpenetration. This occurs with each successive blade 30 because the sheethas been substantially flattened and returned to a more uniformconfiguration by the intermediate engagement of a blade 40 of the holder22. This provides an improved redistribution of the filaments across thetow band, since there are not previously formed spaced apart bundleswhich would tend to preserve their integrity and move as a bundle intothe next groove between the peaks. It must be remembered that the tow isa relatively flexible material and can bend quite easily even though itis being stretch broken. It is by no means a rigid material and itsphysical properties are such that it tends to remain as a cohesive groupof fibers rather than falling apart or being easily separated. Thesestretch broken bundles of fibers, of course, can be pulled apart afterpassing through the machine.

By means of the above apparatus and method the fibers in the tow aresubjected to different degrees of stretching laterally as differentblades act upon them. The bundles of fibers do not tend to remainuniform cohesive groups, but rather are returned to a mass and thenagain reseparated; so that, in operation, the bundles do not preservetheir integrity.

Referring now to FIG. 5 of the drawings, a modification is illustratedwherein blade holder 21 has eight blades 30 and the other blade holder22' has seven blades 40 to distribute the wear. By using blade holders21 and 22 which differ in the number of blades from one another by oneblade, each saw-tooth blade 30 or 36 will eventually intersectbetweenall pairs of straight blades 40, thereby evening out the wearingon the straight blades 40.

It will be understood that various changes in the details, materials andarrangement of parts which have been herein described and illustrated inorder to explain the nature of this invention, may be made by thoseskilled in the art within the principle and scope of the invention asexpressed in the following claims.

In particular, the blade configuration, the speed at which the device isrun, and the type of material are all factors which will affect theperformance of this device. These can be adjusted by one skilled in theart to provide the desirable end pattern by making use of the abovedisclosure of my invention. It is noted, in particular, that bladeshaving smooth clean surfaces free from burrs or nicks are desirable,since such defects in the blade surface tend to grab and cut the fibersrather then allowing them to be continuously stretch broken.

It will further be understood that the Abstract of the Disclosure setforth above is intended to provide a non-legal technical statement ofthe contents of the disclosure in compliance with the Rules of Practiceof the United States Patent Office, and is not intended to limit thescope of the invention described and claimed herein.

What is claimed is:

1. During the process of converting a continuous filament syntheticfiber tow into staple length sliver by stretch breaking, the improvementwhich comprises the steps of:

a. advancing the tow under tension;

b. deflecting the tow transversely and laterally and forming it intobundles;

c. flattening and spreading the bundles toward one another; and

d. then redividing the flattened spread bundles to even the tow whilesimultaneously differentially laterally deflecting and stretch breakingthe tow filaments.

2. The invention of claim 1 wherein the individual filaments of the toware differentially drawn across a flat surface.

3. An apparatus for converting a continuous filament synthetic fiber towinto a staple length sliver by stretch breaking, comprising:

a. a first set of draft rollers;

b. a second set of draft rollers for imparting a tension to the towbetween said sets of rollers; and

c. a deflecting means between said sets of rollers for deflecting thefilaments in the tow both transversely and laterally and for evening thetow as it is being stretch broken, said deflecting means comprising apair of rotating blade holders each having a plurality of bladestherein; the blades in one holder having free surfaces for engagement wjh the tow, said surfaces being curved so as to provi e peaks and valleysfor engaging the face of said tow; the blades of the other blade holderhaving edges for engaging said tow which are straight; the holders beingarranged to rotate so that the straight edged blades engage a face ofthe tow opposite from the face engaged by the blades on the otherholder; the blades of one holder alternating with the blades of theother holder in engaging the tow.

4. The invention of claim 3 wherein one blade holder has more blades onit than the other blade holder.

5. The invention of claim 3 wherein the holders are so arranged withrespect to one another and with respect to the tow that the individualfibers of the tow are differentially drawn laterally across the flatstraight surfaces of the straight blades during stretch breaking.

* g;gg I UNITED STATES PATENT ()FFICE CERTIFICATE OF CORRECTIQN PatentNo. 3,696,467 Dated OC CObel" 10', 1972 Inventor(s) James ohrke, Jr

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Col. l, Line 6 delete "24" and insert -27-- C01. 2, Line 10 delete "two"and insert --tow-- Col. 3, line 51 after "quarter of" insert --thepitch-- Signed and sealed this 27th day of March 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. During the process of converting a continuous filament syntheticfiber tow into staple length sliver by stretch breaking, the improvementwhich comprises the steps of: a. advancing the tow under tension; b.deflecting the tow transversely and laterally and forming it intobundles; c. flattening and spreading the bundles toward one another; andd. then redividing the flattened spread bundles to even the tow whilesimultaneously differentially laterally deflecting and stretch breakingthe tow filaments.
 2. The invention of claim 1 wherein the individualfilaments of the tow are differentially drawn across a flat surface. 3.An apparatus for converting a continuous filament synthetic fiber towinto a staple length sliver by stretch breaking, comprising: a. a firstset of draft rollers; b. a second set of draft rollers for imparting atension to the tow between said sets of rollers; and c. a deflectingmeans between said sets of rollers for deflecting the filaments in thetow both transversely and laterally and for evening the tow as it isbeing stretch broken, said deflecting means comprising a pair ofrotating blade holders each having a plurality of blades therein; theblades in one holder having free surfaces for engagement with the tow,said surfaces being curved so as to provide peaks and valleys forengaging the face of said tow; the blades of the other blade holderhaving edges for engaging said tow which are straight; the holders beingarranged to rotate so that the straight edged blades engage a face ofthe tow opposite from the face engaged by the blades on the otherholder; the blades of one holder alternating with the blades of theother holder in engaging the tow.
 4. The invention of claim 3 whereinone blade holder has more blades on it than the other blade holder. 5.The invention of claim 3 wherein the holders are so arranged withrespect to one another and with respect to the tow that the individualfibers of the tow are differentially drawn laterally across the flatstraight surfaces of the straight blades during stretch breaking.